Indexable cutting inserts for cutting tools include, for example, cutting inserts made of carbide, ceramic, coated carbide, coated ceramic, or other hard materials. Such inserts generally have multiple cutting edges located at various corners or around peripheral edges of the inserts. In a conventional arrangement, cutting inserts are mechanically secured to a tool holder, and are removable in relation to the tool holder, and may be readily re-positioned (i.e., indexed) to present a fresh and new cutting edge to engage a workpiece. A tangential cutting insert refers to a cutting insert that lies flat around the cutting diameter of a tool holder with its fastener hole axis pointing to the cutting axis of a cutting tool. A tangential cutting insert presents the strongest cutting section (i.e., largest thickness) against the main cutting force which is the tangential component of the cutting force at the cutting diameter.
In conventional designs for positioning multiple cutting inserts in a tool holder to form a cutting flute comprising a combined sinusoidal and helical cutting edge in a cutting tool system, the shape of the cutting insert is limited to either a generally rectangular shape or a generally square shape. For a generally rectangle or square cutting insert, the cutting edge length and the total cutting insert length is about the same. In order to form a cutting flute comprising a combined sinusoidal and helical cutting edge, there is not enough space to build a strong insert-receiving pocket in the holder to receive the common cutting inserts. The insufficient space can cause weaker and less stable support for a cutting insert with sinusoidal and helical cutting edge while seating in the pocket of a tool holder.
Furthermore, the complex cutting edges of conventional indexable sinusoidal and helical cutting inserts can require pockets having complex surfaces to receive the inserts. The complex edges and surfaces can create weak connections that cause a reduction in performance during cutting operations.